29 November 2010

The Origins of Red Flag

I had started this blog out as a way of sharing a lot of the interesting aviation history I come across in the course of my reading. I'm a bit attention-deficit when it comes to reading, I usually jump between numerous books at once as I've really never been able to read one book straight through then start another. The benefit of this little quirk of mine is that what I post in this blog can be quite varied. Most of the time as I'm reading, I'll put a little dog ear on pages that I think have good material for this blog and over time, you can guess that most of my aviation books have little dog ears in the lower corners. I'll have several possible topics rattling around in my head at any given time and then when I have the chance to sit down and start a post, it's just a matter of seeing which one topic I've been ruminating over comes easiest to type! The topic I had planned for today got postponed as I learned via my regular Twitter stream this morning that on this date thirty-five years ago the first Red Flag exercise was held at Nellis AFB, Nevada. I just happen to be currently reading Steve Davies' wonderfully engaging book Red Eagles: America's Secret MiGs and it details the origins of the now-famous combat aircraft exercise that is held several times a year at Nellis. 

This past weekend I had posted about those first secret MiGs that operated out of Area 51/Groom Lake. The operational exploitation of the MiGs was but one of the first steps taken by the US Air Force and the US Navy to reverse the sagging fortunes of US fighter pilots over the skies of Vietnam. In 1966 the Tactical Fighter Weapons Center (TFWC) was established at Nellis AFB as the leading school house of fighter tactics evaluation and training. One of the keys to the TFWC was making use of the 12,000 square miles of uninhabited desert terrain north of Nellis that gave in the words of Steve Davies "the playground for America's finest fighter pilots". One of the earliest projects based out of the TFWC was the "Red Baron" reports. Since 1966 the Department of Defense's Weapon Systems Evaluation Group had been collecting a wealth of information on every one of the 320 MiG encounters in Vietnam until July 1967 that involved either the McDonnell F-4 Phantom or the Vought F-8 Crusader. That exhaustive data set became Volume I of Red Baron. Volumes II and III analyzed another 259 MiG encounters by Republic F-105 Thunderchiefs as well as other US aircraft. That three-volume set of data became Red Baron I. In 1969, Red Baron II covered 625 MiG encounters from 1967 to the end of Operation Rolling Thunder at the end of 1968. Later, Red Baron III completed the comprehensive analysis of the air war. 

The Red Baron reports were incredibly detailed with interviews of crew members and pilots with questions to be answered such as "Where were you when you first saw the bogeys?" or "What altitudes and speeds were being used in setting up the engagement?". The bottom line of the Red Baron reports was quite simply that American fighter pilots in Vietnam were not familiar enough with fighting dissimilar aircraft- what was needed was DACT- Dissimilar Air Combat Training. Red Baron went even further, recommending that the USAF provide its fighter pilots with realistic enough training based on the detailed study of all of the MiG encounters in the classified reports. One recommendation was the use of actual enemy aircraft (which stemmed from the programs I posted about this weekend) or realistic substitutes. That recommendation led to the formation of the USAF Aggressors, units operating Northrop T-38 Talon trainers and F-5E Tiger II fighters as surrogates for enemy MiGs. The pilots of the Aggressors specialized in emulating Soviet tactics, even using their own organic GCI controllers. 

The first Aggressor squadron stood up at Nellis AFB in the summer of 1972, but some of the founders and proponents of the Aggressors wanted to push the training even further. While the first Aggressor squadrons were wildly successful to the point that two overseas Aggressor squadrons were established (one in the Philippines at Clark AB for PACAF and one at RAF Alconbury for USAFE), it was a well-known fact from the Red Baron reports that new fighter pilots in the skies over Vietnam had a disproportionately low life expectancy. Other USAF studies had shown that the majority of combat losses (even outside of Vietnam) occurred within a new pilot's first ten combat missions. Once getting the eleventh combat mission, a new pilot's survival chances quickly improved due to experience. The solution was an elegant one that dovetailed nicely with the mission of Nellis AFB, that of the Aggressors as well as the secret MiG force then based at Area 51/Groom Lake. Recreate the first ten combat missions for pilots in the training environment at Nellis AFB using not only the Aggressors and the MiGs, but also the air-to-ground ranges to improve the accuracy of strike aircraft crews. In May 1975, the Tactical Air Command commander, General Robert J. Dixon, gave his approval for the formation of Red Flag with the first exercises to be held in six months. 

In that hectic six months, the most realistic training environment was created at the weapons ranges north of Nellis AFB. Not only were there to be fighter and strike aircraft, but also electronic warfare aircraft, transports and tankers. Reconnaissance assets would participate. Captured Soviet radar systems and facsimilies were arrayed in the ranges along with an integrated missile and anti-aircraft gun defense system. Targets were laid out and finally, the Aggressors would play the part of enemy MiGs (eventually even the secret MiG force participated). Right on schedule, on 29 November 1975, Red Flag I took place with 37 aircraft, 561 personnel and a total of 552 sorties were flown.

Today's Red Flag is a three week exercise in which entire squadrons deploy with their maintenance and support personnel as if on a wartime deployment. The average Red Flag exercise will have around 100 aircraft with several thousand personnel. Units from all branches of the US military participate as well as Allied nations where an invitation to Red Flag is considered an honor and testament to a foreign unit's professionalism. Since that first Red Flag exercise thirty-five years ago today, it's estimated that over half-a-million personnel have been trained, over 300 types of aircraft have participated and well over thiry nations have participated. 

Source: Red Eagles: America's Secret MiGs by Steve Davies. Osprey Publishing, 2008, p24-37.

27 November 2010

How A Top Secret Program Restored American Air Superiority

At the height of the Vietnam War, the skies were filled with technologically-advanced American aircraft from both the US Navy and the USAF, yet the air battles were a thread-bare echo of past glories in the 1950s skies over Korea's MiG Alley. By 1967 the Navy had a kill ratio of only 3.7 to 1 (3.7 MiG kills for every Navy fighter lost to a MiG) and the USAF was even worse, with a kill ratio of only 2.2 to 1. By comparison, at the end of the Korean War, the USAF pilots of the North American F-86 Sabre alone had a kill ratio of 10 to 1. While various studies and reports like the Navy's Ault Report offered many suggestions, the basic fact of the matter was that the art of dogfighting as a skill had been lost. In the USAF, for instance, the solution in the 1960s to an increasing accident rate in the McDonnell Douglas F-4 Phantom II was to simply ban air combat maneuvering training (ACM)- the accident rate fell, but legions of Air Force Phantom drivers entered the skies of Vietnam with little experience in knowing that their aircraft could and couldn't do in a dogfight with North Vietnamese MiGs. While a the solutions that eventually restored American supremacy in the skies are complex and beyond the scope of today's blog post, the foundations were being laid down in the black world in the latter half of the 1960s. 

The story begins on 16 August 1966 in the Middle East. Operation Rolling Thunder, the sustained air bombardment of North Vietnam, had begun the year prior and would continue until 1968. Monir Radfa, an Iraqi Air Force captain, took off in his Mikoyan MiG-21F from Rashid AB outside of the Iraqi capital for what was supposed to be a local navigation exercise. Instead, he made a dash to the southwest at low level, intending to defect to Israel. The Jordanians failed to intercept him as he streaked low across their country, the RJAF's Hawker Hunters too slow at low level. Once over Israel, he lowered his landing gear and wagged his wings to two intercepting Israeli Mirage III fighters, signaling his intentions and was escorted to Hatzor AB and given asylum. With the MiG-21 being one of the most potent fighters in the Arab air forces that threatened Israel, they immediately set about flight testing the MiG-21 for over 100 hours over the next 12 months, learning its strengths and weaknesses and teaching the Mirage III pilots (the French delta was the main fighter of the IDF in those days) how to defeat the MiG in a dogfight. Initially hesitant to share its prize with the United States, Israel eventually concluded an agreement brokered by the US Defense Intelligence Agency (DIA) to loan the MiG-21 to the US for study in exchange for being allowed to buy the F-4 Phantom II, the American front-line fighter of the day. At the time the Israelis had made several overtures to the Johnson Administration to purchase the Phantom, only to be rebuffed out of a fear by President Johnson of escalating matters in the Middle East. Now that the Israelis had leverage, the Phantoms would be on their way and the US would finally get to study its vaunted adversary in the skies of Vietnam up close. 

The MiG was disassembled and transported by a Lockheed C-5 Galaxy to the USAF's secret testing base at Groom Lake, Nevada (Area 51). Responsibility for evaluation of the MiG-21 was given to the USAF's Foreign Technology Division (FTD) that was part of the Air Force Systems Command based at Wright-Patterson AFB in Ohio. AFSC assigned all of its programs with the code word prefix "HAVE". For example, the original stealth demonstrator aircraft that gave rise to the Lockheed F-117 Nighthawk was code named "HAVE BLUE". In the case of the MiG-21 on loan from Israel, it was code named "HAVE DOUGHNUT". Two categories of flight testing were performed on the MiG- the first type concerned technical analysis- performance, flight envelope, engineering, structures, and so on. The second part of the tests were operational- the MiG would be flown in mock dogfights against US fighter aircraft. Because AFSC/FTD's emphasis was technical in nature, most of the HAVE DOUGHNUT flying concerned technical analysis. 

The first flight out of Groom Lake took place in January 1968 and continued until April of that year before the MiG was returned to Israel. For three intensive months, the MiG was flown in various profiles to determine how it could be detected by both radar and infrared systems, it flew against the bombers of the Strategic Air Command to see how well the bombers' systems could detect and counter it, and infrared signature tests were carried out using a specially-fitted T-39 Sabreliner that could mount the seeker heads of various missiles in the US inventory. Out of a total of 102 sorties flown as part of HAVE DOUGHNUT, 33 sorties were devoted to operational testing in mock dogfights with the USAF and 25 sorties were devoted to mock dogfights with the Navy. 

Not four months after the end of HAVE DOUGHNUT, two Syrian MiG-17Fs on a navigation exercise got lost and inadvertently landed at an Israeli air base. Acquisition of the MiG-17s was of high importance to the United States as the MiG-17, though slow and dated, was nimble and the main adversary type encountered in the skies of Vietnam. Though limited to subsonic performance, VNAF MiG-17s were flying circles around American fighter pilots leading to the dismal kill ratios I mentioned above. After testing by the Israelis, the two MiG-17s were then turned over to the United States for analysis. The first MiG-17 made its first US flight at Groom Lake in January 1969 with the code name HAVE DRILL. The second MiG-17 then flew in March of that year with the code name HAVE FERRY. Both programs wound down by June 1969 and the findings were shared with the Navy's new TOPGUN school that was established to reintroduce dogfighting skills to Navy pilots. In addition, the findings of HAVE DOUGHNUT, HAVE DRILL, and HAVE FERRY were shared with the instructors at the USAF's Fighter Weapons School at Nellis AFB, Nevada, where they would go on to establish the Red Flag exercises. 

On 25 November 1969 a Cambodian Khmer Air Force pilot defected to South Vietnam in the Chinese copy of the MiG-17F, the Shenyang J-5. The USAF pilot who flew the MiG-17 in HAVE FERRY and HAVE DRILL, Col. Wendell Shawler, was tapped by the AFSC/FTD to go to South Vietnam and make several evaluation flights of the J-5 to establish that it had the same flight characteristics as the MiG-17. This short program of just five flights from Phu Cat AB in South Vietnam was code named HAVE PRIVILEGE. 

As a result of these four top secret exploitation programs, both USAF and Navy fighter tactics were changed and pilots were once again trained to exact as much capability and performance out of the aircraft as possible to win the dogfight. It wasn't until 1989 that a Pentagon official confirmed that in the 1981 combat of two US Navy F-14 Tomcats versus two Libyan Sukhoi Su-17 fighters over the Gulf of Sidra that the tactics used had been developed out of mock combat testing with US-operating Soviet fighters. Not long afterwards, HAVE DOUGHNUT, HAVE DRILL, HAVE FERRY, and HAVE PRIVILEGE were declassified. What didn't get mentioned was that a much bigger program succeeded those programs and would remain top secret for 20 years! But more on that program in a future blog post! 

Source: Red Eagles: America's Secret MiGs by Steve Davies. Osprey Publishing, 2008, p16-20.

26 November 2010

Grumman's Biggest Cat in World War II

In early 1941 the United States Navy issued a requirement to Grumman for development of a large twin-engined fighter powered by twin Pratt & Whitney R-2800 Double Wasp engines of 2,100 horsepower each. The Double Wasp was used on the Navy's other two fighters under development at the time, the Grumman F6F Hellcat and the Vought F4U Corsair- two such engines offered a tremendous leap in performance for what the Navy designated the F7F. The fighter would be heavily armed with four 20mm cannon in the wing roots and four 0.50-caliber machine guns in the nose with provision for carrying a torpedo under the fuselage or two 1,000 lb bombs under the wings. The large fighter would form the nucleus of the air wing of the new 45,000 ton Midway class aircraft carriers then under proposal. On 30 June 1941 the Navy authorized Grumman to begin work on the Tigercat. Two prototypes designated XF7F-1 were ordered on that day. As an interesting historical sidenote, five weeks earlier the US Army Air Force ordered two aircraft as well which were to be designated XP-65 but had lighter Wright R-1820 engines that would have been turbosupercharged to give the XP-65 even better peformance than the F7F. However, the differing specifications of the Navy and the Army were at odds as the USAAF wanted a lighter fighter than what the Navy desired. As a result, what might have been the first American joint-service fighter died quietly when the Army bowed out due to concerns about the design becoming overweight to meet Navy requirements. 

With the first F7F-1 Tigercats rolling off the Grumman production lines in April 1944, the Navy took the unusual step of having the Tigercat only operate with land-based squadrons of the US Marine Corps and skip  what promised to be a lengthy carrier qualification series of tests as the Navy had not previously operated large twin-engined fighters off its flight decks. The aircraft carrier it was intended for, the USS Midway, was still under construction at the time. At that point in the Pacific War the Navy felt that its fighter needs were being satisfied with the F6F Hellcat and the F4U Corsair. The Marines could operate the Tigercat as a fighter bomber which the Navy brass felt was more suited to the aircraft's design. Plans were set in motion to equip twelve Marine Corps fighter squadrons that were operating the Corsair at the time to re-equip with the Tigercat. The Corsairs would then be passed back to the Navy to meet fleet requirements in the Pacific. 

Production of the F7F-1 Tigercat came to sudden halt in December 1944 after only 35 aircraft were built. By this point in the war the Navy's carrier battle groups were gearing up for their first raids on the Japanese Home Islands themselves (Task Force 58 in February 1945) as a diversion for the assault on Iwo Jima. The Navy had a different role in mind for the Tigercat and the third F7F-1 was converted into the prototype XF7F-2N night fighter with an AN/APS-6 radar set in the nose, displacing the four 0.50-caliber machine guns, and a second seat for the radar operator over the wing behind the pilot. More powerful versions of the R-2800 radial were used to compensate for the increased weight of the second crewman and the additional radar equipment. However, changing requirements and technical issues meant that the F7F-2N was only an interim type, with only 65 being produced between December 1944 when F7F-1 production was stopped in favor of the night fighter and August 1945. Several of the -2Ns did go to sea, though, but for a series of comparison tests aboard the USS Antietam and the USS Shangri-La with the North American PBJ-1 Mitchell (the Navy version of the B-25 Mitchell). Both were being evaluated as night fighters by the Navy in April 1945 but it was soon found that both the Tigercat and the Mitchell were too large for the Essex-class fleet carriers and the Navy settled on radar-equipped variants of the F6F Hellcat and F4U Corsair instead. 

Only one Tigercat squadron made it to the Pacific before the end of the war with the Japanese surrender. Marine Corps squadron VMF(N)-533 was one of three Marine Corps night fighter squadrons established in 1943 operating the night fighter version of the Hellcat, the F6F-5N. Based in Okinawa at the time, the squadron was to convert to the night fighter Tigercat in theatre, but their new mounts arrived the day before the Japanese surrender. Patrols were made over China and Japan, but no operational engagements took place in the months following the Japanese surrender. Interestingly, the Royal Navy evaluated two F7F-2N Tigercats in the night fighter role, but decided to adopt the De Havilland Sea Hornet instead for the role. 

The most famous and most-produced version of the Tigercat, the F7F-3 and -3N, didn't arrive until March of 1946, too late for service in the Second World War. This variant was never carrier-qualified as well and by the time the Midway class carriers it was intended for were operational, the Navy's standard fighter was the Grumman F8F Bearcat and jets were just over the horizon. The F7F-4N was fully carrier capable and fully qualified unlike the previous versions, but only 14 of this model were built. In the Korean War, night fighting Tigercats in the hands of the Marine Corps finally drew blood and achieved fame that had eluded it during the Second World War. 

Source: United States Naval Fighters of World War II in Action by Michael O'Leary. Blandford Press, 1980, p136-141.

24 November 2010

Martin Bets on Orlando and Wins the Pershing Missile Contract

I had posted several weeks ago how George M. Bunker, the president of Martin Aircraft that succeeded Glenn L. Martin in 1952, diversified the company by getting into the missiles and rockets business. The year 1956 was a tremendous year for Martin, having won the Air Force's Titan ICBM contract as well as the Navy's Vanguard satellite launcher contract as well. With a major missile contract with the USAF, a major rocket launcher contract with the Navy, no one would have thought that Martin would get an upcoming Army contract for a medium-range ballistic missile. But then again, no one thought Bunker to be a betting man, either. At the time, the Army hadn't even issued a formal Request for Proposals to the industry for such a program. But early in 1956, Bunker paid a visit to Major General John Medaris, the commanding officer of the newly-formed Army Ballistic Missile Agency at Redstone Arsenal in Huntsville, Alabama. It was General Medaris who was the boss of German rocket scientist Werner Von Braun and his team of German engineers. The ironic aspect of the visit was that Bunker didn't stop by to solicit the Army's business. As General Medaris would recount the visit years later, Bunker simply asked "how might the Martin Company could best be of service to the Army's missile objectives." The general didn't offer any specifics on what the Army had in mind, but did point out to Bunker that it would be "extremely advantageous" to the Army if an aerospace company saw fit to have a production facility somewhere between Huntsville and Cape Canaveral Air Force Station, the primary test launch site for all US long-range missile programs. Bunker would thank the general for his time and departed. 

Bunker decided that the best location would be Orlando, Florida, which in 1956 was a quiet banking town surrounded by orange groves and ranches. Most in the aerospace industry only knew of it as it was the nearest airport to Cape Canaveral one hour away. Many reporters, scientists, and engineers transited through Orlando on their way to and from the Cape. In August 1956 Bunker and one of his VPs called on the chairman of Orlando's largest bank, First National Bank, inquiring on the purchase of 500 acres for a manufacturing plant. Before the day was over, Bunker would be introduced to the mayor of Orlando, the head of the Orlando Industrial Board, and one of the city's prominent real estate brokers. A few days later, Orlando city leaders traveled to Baltimore to brief the Martin board of directors on candidate sites. Bunker directed the purchase of 6,400 acres at $200/acre. The site chosen was completely undeveloped and the Martin board asked about the need for roads, sewers, and utilities and that very same day not only did they secure the guarantee from the city leaders to provide all of what was needed, they also secured the support of the governor of Florida. Ground was broken five months later and in December 1957 Martin formally opened its Orlando facility to great fanfare. 

Mind you, Martin had yet to win any contract that would allow them to use that sprawling new facility! To bring their new missiles facility up to speed, several Martin missile programs like the Lacrosse and Bullpup missile programs were moved to Orlando. It would be Martin's third manufacturing facility- the first one being the aircraft plant in Baltimore, the second one being the Titan missile facility outside of Denver. On 7 Janaury 1958, General Medaris formally issued the RfP to industry for a new solid-propellant Army ballistic missile to replace the Redstone rocket. An amazing 121 companies submitted proposals and this was quickly winnowed down to seven with two absolute requirements- ballistic missile experience and a manufacturing plant near Cape Canaveral to facilitate testing. The new missile had a nuclear warhead, had to be road mobile and easily air-transported. The missile had to be easy and quick to deploy and fire by combat units in any weather condition. The seven companies were Chrysler (which was responsible for building the Redstone missile), Lockheed (which was already working on the Navy's Polaris missile), Douglas (which was building the Thor IRBM for the USAF), Convair (who was building the Atlas) as well as Goodyear and Sperry-Rand which had extensive missile systems experience even though the two companies hadn't built a missile. The seventh company was Martin. The seven companies were required to give a four hour presentation to General Medaris and his team on their submission in thirty days. The new missile would be named Pershing in honor of General John J. Pershing from the First World War. 

The Secretary of the Army, Wilber Brucker, was a former governor of Michigan and was under tremendous political pressure to have Chrysler's submission selected for the Pershing contract. General Medaris wasn't going to have any of this on his watch as Martin was the favored submission based on their technical merit and having a manufacturing facility already in place near the Cape in Orlando. In fact, Martin even offered to demonstrate the mobility of their Pershing design by driving it out from Orland to the Cape for test firing. Brucker did attempt to stall the program to prevent Martin's selection but on 22 March 1958 the Army Ballistic Missile Agency awarded the Pershing contract to Martin. 

The first version of the missile, the Pershing I, was mounted on tracked vehicles and was first delivered to Fort Sill, Oklahoma in 1962 where the Army formed its first Pershing battalion. The missiles went on nuclear alert in Europe in 1964, with some of the battalions under joint control with the US Army and West Germany (Geilenkirchen AB, the home of the NATO E-3 Sentry AWACS force, was a former German Pershing base). When the Army wanted to improve the mobility of the Pershing battalions with wheeled vehicles and an even faster reaction time should the order to launch come, Martin quickly developed the Pershing Ia system and in an amazing three-month span in 1969, Martin managed an unique swap system to upgrade the units in Europe. New equipment rolled out of the Martin factory in Orlando and was driven to Port Canaveral. One battalion's worth of equipment were loaded onto a Navy ship and transported to Bremerhaven in Germany, where a Pershing I battalion had driven, met the Pershing Ia equipment being unloaded, and drive it back to their bases. Martin would win a follow on contract for an improved version of the Pershing Ia, the Pershing II, in 1975. A deadly accurate missile, the Pershing II had triple the range of the Pershing I/Ia and could even reach Moscow. From 1958, the Pershing program would run for 34 years and generate $4 billion in revenue for Martin. The program consistently ran under budget and ahead of schedule for its entire life. A total of 754 Pershing I and Pershing Ia missiles were built, as well as 276 of the highly accurate Pershing II missiles as well as all the associated support equipment and land vehicles. 

The role of the Pershing missile in Cold War deterrence cannot be underestimated. The threat and accuracy of the Pershing missile was once described by a former Soviet defense official as a "scapel held to our throats". It was common knowledge that the Pershing missiles targeted Soviet command and control facilities and in a sense, it didn't threaten Soviet forces, it threatened Soviet leadership. On 8 September 1988, then Vice-President George H.W. Bush spoke at the Longhorn Army Ammunition Plant on the occasion of the disposal of the Pershing missile under the terms of the Intermediate Nuclear Forces Treaty: "The Pershing missile system strengthened deterrence and was concrete evidence of United States resolve. If we had not deployed the Pershing, there would not be an INF Treaty today."

Not a bad payoff for a gamble by George M. Bunker back in 1956. Oh, you might be wondering what the "M" stands for in his name- "Maverick".

Source: Raise Heaven and Earth: The Story of Martin Marietta People and Their Pioneering Achievements by William B. Harwood. Simon and Schuster, 1993, p327-348.

22 November 2010

Tactics Over Technology: The Thach Weave

One little known aspect of the June 1942 Battle of Midway was that it wasn't just the turning point in the Pacific War that started to roll back the Japanese Empire, but it also was a turning point in fighter tactics that changed the way air combat was conducted. At the start of the Second World War, US Navy fighter squadrons had eighteen aircraft that were divided into six sections of three planes each- each section was composed of a flight leader and two wingmen. However, well before the attack on Pearl Harbor, the Navy fighter squadrons VF-2 and VF-5 experimented with two-plane sections with a flight leader and a single wingman. In a three-plane section it was found that the wingmen tended to focus too much on formation keeping instead of being on watch for enemy aircraft. The shift to a two-plane section with the wingman staggered and below the lead's altitude lessened the need for strict formation keeping. As a result, the two-plane section became the basic unit of the Navy's fighter squadrons beginning in July 1941. Three sections then made up a division in the squadron for a total of six planes- in cruising, each of the three sections flew in trail, but nearing combat they assumed an echelon formation. Having the support of a single, more vigilant wingman improved the odds of survival particularly against the superior Mitsubishi A6M Zero fighter.

That summer, Lt. Commander John "Jimmy" Thach, commander of VF-3, was still stateside and undergoing conversion with the rest of his squadron in California from the troublesome Brewster F2A Buffalo to the more robust Grumman F4F Wildcat. While there, Thach had access to preliminary reports from the American Volunteer Group "Flying Tigers" in China on the phenomenal performance of the Japanese Zero, possesing maneuverability and a rate of climb well in excess of their new F4F Wildcat mounts. At the time Thach was already well-known to his men for using matchsticks on a table to come up with new tactical ideas for his aircraft. Now he was back to his kitchen table each night, playing with matchsticks trying to come up with a tactic to counter the exceptional maneuverability of the Zero. Thach's first conclusion was the standard three-section division was unsuitable. It was better to use just two sections with a total of four planes. But how to use them? Thach would deploy two sections of Wildcats flying abreast of each other at a distance that approximated the turning radius of the Wildcat. Because of their positioning abreast and at a distance, each section had a good view of the other section's six-o'clock position. When Zeroes engaged, they'd be forced to choose one section to attack and could be spotting by the other section. This is one key characteristic that set apart what Thach called his "beam defense position" from other similar weaving tactics- a commitment to be on lookout for the other section. 

Once a section was attacked, the other section either signaled the other one or just turned in towards that section under attack. Once alerted, the section under attack turned towards the incoming section. If the Zero pressed its attack, it faced a head on attack from the incoming section and if it withstood that, it would find itself in a position with the incoming section having another firing pass as each section weaved in and out from each other. If the Zero broke off the attack, then it faced having the incoming section getting on its tail. Thach also considered that the weave could also work on with just a single section if one fighter was engaged, the other fighter in the section could set up the weave. Wanting to prove it worked, Thach decided to test his ideas with the pilots of VF-3. Four planes were to play the part of the defenders flying in two sections. Thach was one of them. Another group of squadron pilots would play the part of the attackers- in his tests, Thach selected his best pilot, future Medal of Honor winner Edward "Butch" O'Hare, to lead the attacking group. To simulate the performance advantage of the Zero, Thach and the "defending pilots" would limit their Wildcats to just 1/2 power while O'Hare and the attacking pilots would get to use the full power of their Wildcats. Instructed to attack from different angles and altitudes, O'Hare found that once the "defenders" set up the weave from their beam defense position, they always found themselves facing the guns of one section or the other irrespective of their performance advantage. 

At the Battle of Midway, VF-3, led by Thach, were embarked on the USS Yorktown. Tasked with covering a group of plodding Douglas TBD Devastators, Thach was leading two sections at higher altitude. When the Devastators were jumped by Zeroes, Thach was unable to fly to their aid as his group had also been attacked by a group of Zeroes. In their initial firing pass, one of the four Wildcats was downed, but Thach had the remaining Wildcat set up a weave with his section. In short order, three Zeroes were shot down as the Zero pilots tried to aim on the weaving Wildcats and found themselves exposed to Thach and his men on repeated firing passes. Although Thach wasn't able to save the Devastators, the "Thach Weave" proved its worth in battle and word spread amongst Wildcat pilots that they now had a tool with which to fight the much-vaunted Zero. 

Thach's tactical genius was recognized after Midway and later in the war developed what was called the "Big Blue Blanket" defense against kamikaze attacks which was a layered defense using round-the-clock combat air patrols of Grumman F6F Hellcats and Vought F4U Corsairs as far away as possible from the carrier to catch the kamikazes early. Fighter sweeps were conducted over Japanese airfields to prevent kamikazes from getting airborne, and destroyer radar pickets were stationed as far as 50 miles from the main carrier force. During the Korean War Thach commanded the carrier USS Sicily and then after the war, captained the USS Franklin D. Roosevelt. In 1959 he was assigned to the Navy's antisubmarine warfare development unit with the ASW carrier USS Valley Forge as his flagship. His contributions to ASW tactics were so significant he was featured on the cover of Time Magazine and the Thach Award was later established for the best ASW squadron in the Navy. The Perry-class frigate USS Thach (FFG-43) is named in his honor. 

But he is best known for the Thach Weave and basic principles of the weave are still in use to this day in modern fighter combat. The Thach Weave was also used by Doulgas SBD Dauntless dive bombers in the Pacific- being much slower, the Dauntless were vulnerable to the Zero as well, but by employing the Thach Weave, the rear gunner of the Dauntless, having twin machine guns at his disposal, would have a much clearer shot at the attacking Zero during a weave. 

Source: United States Naval Fighters of World War II in Action by Michael O'Leary. Blandford Press, 1980, p62-63.

18 November 2010

The Cadillac of the Constellation Line

Through the 1950s Douglas and Lockheed engaged in a rivalry to create the ultimate propliner as each company successively improved its product line to appeal to the rapidly expanding passenger market. Douglas' DC-6 led to the more powerful DC-7 and even with this aircraft, the design was pushed even further with the DC-7C. In addition to more power and fuselage stretch, the "Seven Seas" also had a constant-chord wing-root section added inboard of the engines. Not only did this move the loud radials five feet further away from the passenger cabin, it also increased the aspect ratio of the wing, reduced drag, and provided more space for internal fuel. The DC-7C could now outperform Lockheed's flagship propliner, the L-1049G Super Constellation, in terms of speed, range, and payload, allowing all-year round nonstop trans-Atlantic service. Not to be outdone, Lockheed briefly considered a turboprop Constellation, the L-1449, using the new Pratt & Whitney T34 engine (which was used on the Douglas C-133 Cargomaster). While military Constellations did flight test both the T34 installation and the Allison 501 turboprop (military versions of which were used on the C-130 Hercules and P-3 Orion), Pratt & Whitney balked at the use of the T34 as they felt Lockheed was pushing the engine too far. 

Scrapping the L-1449 out of the dispute with Pratt & Whitney, Lockheed took the new wing design it had developed for the turboprop L-1449 and grafted it on a stretched L-1049 Super Constellation fuselage to give birth to what many consider to be one of the ultimate piston engine airliners, the L-1649 Starliner. The wing was modified to accept the powerful Wright R-3350-18EA Turbo Compound radial engines which were originally developed to power the Navy's Lockheed P-2 Neptune patrol bomber. The 18-cylinder R-3350 instead of using a turbocharger for high altitude performance had power recovery turbines instead (PRTs)- one PRT collected the exhaust gases from six cylinders to deliver more power back to the engine crankshaft, providing a 500 horsepower boost. The same engines were used on the DC-7C as well. The long wing of the Starliner gave it the highest aspect ratio wing of any propliner, 12:1, and this translated to improved performance over the DC-7C. Nearly 2,000 gallons more of fuel could be carried compared to the Super Constellation. Like the DC-7C, the longer wing put the inboard engine nacelles further away from the passenger cabin. 

The Starliner made its first flight from Burbank on 10 October 1956. Amazingly, only three Starliners were used for a short 251-hour flight test program to get airworthiness approval on 19 March 1957. With a cost of $3 million per aircraft, TWA inaugurated L-1649 Starliner services on 1 June 1957, exactly one year to the day that the Douglas DC-7C was introduced into service. Though the DC-7C was faster, the Starliner had a longer range as well as a quiet and smooth ride thanks to increased sound insulation in the cabin and a flexible wing that dampened inflight turbulence. TWA marketed its Starliners as "Jetstream Starliners" and on marketing artwork, the wingspan of the Starliner was exaggerated to make the engines appear further from the fuselage than they were. In addition, artists cleverly depicted the Starliner without propellers, much to the ire of competing airlines that cried foul over the advertising campaign they called deceptive. TWA's famous inflight Ambassador Service was upgraded for the Starliners. The passenger seats were called "Siesta Sleeper Seats" that had pull out foot rests and a deep seatback recline that were nearly as comfortable as the sleeper berths which of course were still available on the Starliner's long routes. In the lounge area of each Starliner were cabin wall murals created specifically for TWA's aircraft by the artist Mario Zamparelli that showcased TWA's overseas destinations. 

The long range of the L-1649 Starliner allowed TWA to open up polar routes from the US West Coast to Europe. The inaugural TWA polar flight, Polar Flight 801, set a world record for the longest piston engine airliner flight on 2 October 1957 when flying westbound from London to San Francisco, encountered strong headwinds that resulted in a marathon 23-hour 19-minute nonstop flight. As impressive as the capabilities of the Starliner were, only TWA, Air France, and Lufthansa would be first-liner operators as few of the world's airlines had a route network and passenger traffic that made the Starliner economical. The Starliner only flew first line services for less than three years before getting displaced by the Boeing 707 and as a result of coming to market one year later than the Douglas DC-7C, only 44 Starliners were built compared to 121 DC-7Cs. When the final L-1649 Starliner was rolled out of the Burbank factory on 12 February 1958 for Lufthansa, it wasn't just the last Starliner but it was the end of the line for the Constellation family that stretched back to 1943. 

One interesting side note from TWA's operation of the Starliner came about due to reliability issues with the R-3350 Turbo Compound engines. While they were some of the most powerful piston engines ever flown, they were a maintenance nightmare compounded by the intricate plumbing work of the three power recovery turbines. In fact, TWA mechanics joked that PRT actually stood for "Parts Recovery Turbine". To minimize the disruption caused by engine failures, TWA acquired a military surplus Fairchild C-82 Packet transport that had a Westinghouse J34 engine in a dorsal nacelle as a jet booster. Nicknamed "Ontos" (the Greek word for "thing"), the C-82 could carry whole R-3350 Turbo Compound engines and a maintenance team to outlying stations where a Starliner might be stranded. Even though the Starliner would be phased out of TWA service, the airline kept Ontos in service to carry spare jet engines for the Boeing 707 and even the Boeing 747, finally retiring the odd bird in January 1972. 

Source: From Props to Jets: Commercial Aviation's Transition to the Jet Age 1952-1962 by Craig Kodera, Mike Machat, and Jon Proctor. Specialty Press, 2010, p77-85. 

17 November 2010

The Very Unorthodox Bartini/Beriev VVA-14/14M1P

I had posted back in August about how in the 1960s, the Soviet Union's lack of a blue-water navy in countering the American ballistic missile submarine fleet led to a Beriev proposal for a unique multirole ocean-going flying boat, the A-150. The basic idea of Soviet naval strategists of the day was that airborne anti-submarine forces would offer a rapid means of seeking out and destroying the SSBNs while building up its own blue-water forces.  While the Beriev A-150 never flew, another aircraft design stemming from the same basic requirements did actually fly. By the time of the new Soviet naval requirements in the 1960s, Italian designer Robert Bartini had already established himself in Russian aviation development having been an emigrant to the Soviet Union in 1923. Already known for his unorthodox approach to aeronautical problems, Bartini had long been studying the use of ground effect to improve aircraft performance. While Rostislov Alexeyev would be the name most identified with wing-in-ground effect (WIG) vehicles, or ekranoplans, Bartini's work late in his life were better described as "ekranolyots", or a vehicle that was capable of both ground effect flight like ekranoplans but also could fly at higher altitudes like normal aircraft. It was in 1965 that Bartini suggested the design of a large ocean-going VTOL amphibian anti-submarine aircraft designated VVA-14. "VVA" was the Russian acronym for a VTOL amphibian and "14" referred to the number of engines he planned to use. 

Bartini wanted VTOL performance so the VVA-14 could operate free of airfields and could be deployed and operated from any location on the Soviet periphery. In addition, its large size allowed it to float with engines off on the surface while it carried out searches for enemy submarines. The VVA-14 could transit to its patrol areas as a conventional aircraft at high altitude, and then begin its search for enemy subs as an ekranoplan. If needed, the VVA-14 could alight on the water and continue its search silently as it would not emit any of the same underwater noises as a conventional surface vessel. On 11 November 1965 the Soviet Council of Ministers granted its approval to Bartini's proposal and issued a set of operational specifications for the design that included two cruise engines, up to twelve lift jets for VTOL flight, a cruising speed of approximately 450 mph, a service ceiling of 39,000 feet, and a 2,800 mile range while carrying a 4,000+ lb weapons load. 

Unlike the ekranoplan layouts developed by the Alexeyev design bureau, the Bartinin VVA-14 used a thick wing center section that also housed the main fuselage and two Soloviev D-30 turbofan engines in dorsal nacelles. On each side of this center section were the large sponsons that not only held fuel, but also housed inflatable pontoons, giving the VVA-14 a catamaran layout when alighted on the water. Outboard of the sponsons were traditional high-aspect ratio wings. The twelve Kolesov RD36 lift engines were to be housed in the thick center wing section and not only provided vertical lift but also provided a cushion of air that was trapped between the large sponsons and the wing center section, making the VVA-14 an augmented wing-in-ground effect vehicle or ekranoplan. The VVA-14 had a bicycle landing gear with a two-wheel nose gear and a four-wheel aft gear with outrigger gears under the sponsons. 

As Bartini's design bureau (or OKB) lacked any production facilities of its own, construction of the VVA-14 prototypes was entrusted to the workshops of the Beriev OKB at Taganrog on the Sea of Azov. Two prototypes were to be built, and as the lift engines and inflatable pontoons weren't ready at the time, the VVA-14 prototype made its first flight from a conventional runway on 14 September 1972. By 1974 the inflatable pontoons were fitted and the first waterborne tests were successfully completed. By the middle of 1975 the VVA-14 had made 107 fairly uneventful flights, but the Kolesov lift engines were still not available for installation. Frustated with the lack of progress from the Kolesov engine bureau, Bartini decided forgo VTOL performance and had a second pair of Soloviev D-30 turbofans installed in pods on each side of the forward fuselage. The exhaust from the forward pair of D-30 engines would create a cushion of air under the wing center section, not unlike the arrangement favored by the Alexeyev OKB. 

The modifications were completed after Bartini's death in 1976. The forward fuselage had to be extended and  a large flap was added to the aft of the wing center section to "capture" the exhaust efflux from for forward pair of D-30 engines. Since the aircraft was no longer a VTOL, the designation was changed to 14M1P. More changes were made, the biggest one of which was the abandonment of the lightweight inflatable pontoons for a conventional flying boat hull under each sponson. This added considerable weight to the 14M1P and the first flight tests found that it no longer would leave the runway when tested out of the water. Water tests proved to be as equally unsuccessful, no matter what was done, the 14M1P refused to take to the air. Successive modifications failed to solve the problem by 1977, the Soviet Navy lost interest and the project was cancelled. Only one of the two original VVA-14 prototypes was completed and it was this prototype that became the 14M1P. In a partially disassembled state, it was donated to the Russian Federation Central Air Force Museum at Monino in 1987, where it remains to this day in poor condition, a mute testament to Bartini's unorthodox methods. 

Source: Russia's Ekranoplans: The Caspian Sea Monster and other WIG Craft (Red Star Series Volume 9) by Sergey Kommissarov. Midland Publishing, 2003, p43-56.

16 November 2010

The Lockheed C-5M Super Galaxy

The first production group of Lockheed C-5 Galaxy transports, designated the C-5A, were built in the 1970s and even then, there were issues with the jet's reliability. When the production line was reopened during the Reagan-era defense buildup in the 1980s, the C-5B was produced to introduce a variety of systems improvements aimed at boosting the jet's reliability. But the mission capable rate of the Galaxy continued to decline. In the mid-1990s, of the 126 C-5A/Bs in service at the time, up to 32 percent of them were down for maintenance at any one time. Of all the aircraft operated by the Air Mobility Command of the US Air Force, the C-5's mission capable rate was the worst, even worse than the 1950s-1960s vintage KC-135 Stratotankers! In 1998 the USAF initiated the AMP (Avionics Modernization Program) which improved many of the cockpit and traffic management systems of the aircraft. Despite this, the mission capable rates continued to deteriorate. By 2001, only 60% of the Galaxy fleet was operational at any one time. The airlift buildup for Operation Enduring Freedom in Afghanistan initially turned things around as increased funding for C-5 maintenance to operate the logistics air bridge to Afghanistan raised the mission capable rate to 75%. But the pace of airlift missions eventually took their tool on the Galaxy- there are reports of one operating location that was allotted ramp space for eight C-5s to be present and the unspecified base had twenty-two C-5 aircraft present, down for maintenance issues! The 2009 troop surge into Afghanistan further strained Galaxy operations with aircraft down for maintenance a fixture on the ramps at Ramstein AB in Germany and NAS Rota in Spain. Personnel joked that AMC stood for "Airplane Might Come".

Two overlapping upgrade programs took place to improve the C-5's abysmal reliability. The first one was the aforementioned AMP (Avionics Modernization Program) that started in 1998 with the last Galaxy coming out of the program in August 2009, with 55 C-5s (50 C-5Bs, 2 C-5Cs, and 3 C-5As) having went through AMP. The second program was the bigger one and addressed the weak link the Galaxy today- it's elderly TF39 engines. The Galaxy's TF39 turbofan engines are the world's first production high-bypass turbofan engine. GE began development of the TF39 in 1965 and on today's unmodernized C-5 Galaxy, represents 40+ year old technology that has long been surpassed by modern commercial turbofan engines. To address this capability gap, Lockheed and the USAF began the RERP program (Reliability Enhancement and Re-engining Program) which began in 2006.

With the announcement that the USAF was to end procurement of the C-17A Globemaster III after 223 aircraft, the modernization of the Galaxy took on added importance. RERP is costly- it's estimated that what is spent on each C-5 going through RERP is equal to buying two C-17A Globemaster IIIs. When each C-5 is delivered to Lockheed's facility in Marietta, Georgia, the first task is to remove the elderly TF39 engines and any last remaining amount of fuel from the aircraft, after which it is moved into a special modification bay for 18 months where nearly 11,000 feet of wiring is pulled out of the aircraft and replaced with modern systems. The most challenging part and part of what makes RERP so costly is the re-engining with the modern GE CF6-80C2 engines. Because of the 30+ years of wear and tear on each Galaxy, a special laser system is used to determine the optimum location for the pylon fittings- in effect, each C-5 going through RERP gets custom-made engine pylons.

Ironically the GE CF6-80C2 engine that replaces the TF39s was derived from the TF39. Designed originally for the Douglas DC-10 and the Airbus A300, the current version of the CF6 is the CF6-80C2 which entered commercial service in 1985. The -80C2 engine powers the two latest versions of the A300 (the -600 version), the two versions of the A310, four versions of the 767 family, three versions of the Boeing 747-400, and the McDonnell Douglas MD-11. Although the basic engine architecture is the same, the CF6-80C2 is much more efficient and modern engine than it was over thirty years ago when it first came to market. What this does to the Galaxy is nothing short of impressive. The addition of modern engines gives the C-5M Super Galaxy 22% more thrust, a one-third shorter takeoff roll, twice the climb rate, and for a given payload, just over 1000 miles more range. And this is before getting into areas like meeting strict noise standards at many of the world's airports when the C-5M has to fly into and out of those locations.

The first Super Galaxy, tail number 86-0013, a C-5B, was rolled out on 16 May 2006 and made its maiden flight on its new engines the following month on 19 June 2006. Following a successful flight test program, the first two examples were delivered to the 436th Airlift Wing at Dover AFB, Delaware. This past summer two C-5Ms joined eight C-5A/Bs on a marathon airlift effort to delivery Army helicopters from NAS Rota (where they had been delivered by ship) to Afghanistan. The eight older Galaxy transports accounted for 23 missions altogether, while the C-5Ms by themselves accounted for 22 missions! Despite having flown one less mission, the two C-5Ms accounted for 55% of the cargo delivered during that operation and boasted a mission capable rate of 96%, something that the Galaxy has never attained in its operational history previously.

Source: Combat Aircraft Monthly, November 2010, Volume 11, Number 11. "New Life in the Galaxy: Deep surgery renders cheaper, more powerful C-5M" by David Axe, p30-35.

12 November 2010

Foxbats Over the Sinai

By 1971 the Soviet Union had built up the Egyptian Air Force to unprecedented levels in the Middle East in the years since the 1967 Six-Day War when the Israelis caught the majority of the Egyptian air arm on the ground. Despite the rearmament effort and 20,000 military advisers, the Egyptians were still in no position to confront the Israeli Air Force over the Sinai. The three-year War of Attrition between Egypt and Israel ended in 1970 when President Nasser of Egypt died of a heart attack. With no gains being made by either side, Nasser's successor, Anwar Sadat, ended the campaign and set about the planning of what would be the 1973 Yom Kippur War. While direct Soviet military involvement was out of the question given the atmosphere of detente that was building between the Soviet Union and the United States, Soviet Premier Leonid Brezhnev authorized the deployment of a reconnaissance task force of MiG-25 "Foxbat" aircraft to Egypt to scout the Israeli defenses on the east bank of the Sinai. It was a bold decision given that most new Soviet aircraft are kept secret for several years, let alone deployed overseas. Operational testing of the Foxbat began in 1970 and there were a multitude of technical problems uncovered that left both the Soviet Air Force (VVS) and the Air Defense Forces (PVO) reconsidering accepting the aircraft for operational service. 

The Deputy Minister of Aircraft Industry, Aleksey Minayev, was a former engineer with OKB Mikoyan who had participated in the development of the MiG-25 before assuming his ministry position at the Kremlin. Being well aware of the VVS and PVO hesitations with the new aircraft, it was Minayev that suggested the deployment of the Foxbat the Middle East in the reconnaissance role. He had no trouble in getting the military to agree to the idea as they were anxious to really see the aircraft operate in a realistic environment to see what it could do and decide then whether or not to proceed with the deployment of the aircraft. It was agreed that the interceptor version of the Foxbat would be unsuitable for the deployment as that would have been considered an overt act and a small handful of interceptors would have been unable to hold off the Israelis. Discussion within the Kremlin came to a consensus that sending the reconnaissance version would do more good as they could provide information on the Israeli defenses in the Sinai. 

Four MiG-25s that were undergoing operational testing were selected for deployment. Two aircraft were MiG-25Rs, which was a pure reconnaissance variant and the other two were MiG-25RBs that were dual-role reconnaissance/strike aircraft. Ironically, the RB variant of the Foxbat came about due to a perceived need for a high-speed strike aircraft to counter the Israeli's deep penetration flights with McDonnell F-4E Phantom IIs during the War of Attrition to knock out Egyptian targets. The formal deployment orders were issued in March 1971 and a team of test program technicians that were ironing out the Foxbat's bugs would accompany the task force to Egypt. To save time, the personnel were flown to Cairo-West AB in Egypt aboard Antonov An-12 "Cub" transports and the Foxbats had their wings, tails and engines removed for transport about Antonov An-22 "Cock" transports. However, it was found that even stripped down, the MiGs were just barely too wide and too high to fit into the An-22 cargo hold as the main landing gears were getting stuck in the aft cargo door. A technician suggested reversing the main landing gear legs so they pointed inward and replacing the mainwheels with those from a MiG-21. This provided enough clearance to get the MiGs aboard for transport to Egypt. At Cairo-West, the Egyptians had already built hardened aircraft shelters for the Foxbats and the Soviet team reassembled the Foxbats inside the shelters. 

The first test flights began in April over Egyptian territory. The design bureau for the Foxbat's massive R15B-300 engines, OKB Tumansky, also had a team in place that managed to tweak the engines to allow the Foxbat to "sprint" at full afterburner for a full 40 minutes, well over the previous three minute limit used in operational testing in the Soviet Union. The first operational reconnaissance mission took place on 10 October 1971. Operating in pairs, two MiG-25s streaked up the Mediterranean coast from the Nile Delta to the Israeli-Lebanese border at 70,000 feet at high speed only 17 miles off the Israeli coast. Interceptions were attempted by F-4 Phantoms but failed to engage the Foxbats. A month later, a single MiG-25 overflew the northern Sinai to image the Israeli defenses there. This time the Israelis had two stripped down F-4 Phantoms ready which attempted to shoot down the MiG with AIM-7 Sparrow missiles. The missile's proximity fuses failed to cope with the Mach 3 speeds and detonated harmlessly past the speeding Foxbat. After an increasing number of overflights of the Sinai that resulted in failed intercepts, the Israelis were incensed. As the Soviet pilots maintained strict radio silence, the Israelis had no choice but to station F-4 patrols near Cairo-West AB, hoping to shoot down a MiG on takeoff. To counter this tactic, Egyptian MiG-21s from other airbases would converge on Cairo-West when the Foxbats were ready to takeoff. At least two MiG-21s would streak down the runway at low level, followed by the pair of Foxbats and then followed by another two MiG-21s to cover the rear until the Soviet pilots were at speed and altitude out of reach of the prowling Phantom patrols. 

Missions were typically flown in pairs and operated at over 70,000 feet at full afterburner. At Mach 3, a Foxbat pair could cover in just two minutes the entire length of the Suez Canal that separated Egyptian and Israeli forces. Fuel was burned off at 1,000 lbs per minute as the aircraft maintained full afterburner. The inlet ducts would heat up to 608 degrees Farenheint (320 degrees Celsius) and the aircraft skin would measure 577 degrees Farenheint (303 degrees Celsius). Pilots reported the glass canopy was so hot that it would burn their fingers if it was touched during a mission. The cameras operated automatically as the MiGs covered 1 kilometer a second. In addition, the onboard ELINT sensors would pinpoint the locations of Israeli radars, communications nodes, and ECM units. On descent and approach back to Cairo-West, the Foxbats were again met by Egyptian MiG-21s all the way to runway touchdown. Two missions a month were flown and by the end of 1971 the Soviets were making routine deep penetration flights over the Sinai with impunity. Even the Raytheon Hawk SAM units in the Sinai were useless as they were only medium altitude surface-to-air missiles with an engagement envelope that topped off at 40,000 feet. 

By the spring of 1972 the Israelis were protesting the Soviet flights to the United Nations, but it was Anwar Sadat that ended the reconnaissance flights. Frustrated that the Soviets were not training his pilots in the aircraft and that it was not being offered to him for sale, the last straw came after a superpower summit when both Brezhnev and Nixon agreed on maintaining the status quo in the Middle East. Realizing that the Soviets were not going to help him retake the Sinai, Sadat ordered nearly all of the Soviet advisers out of the country and preceded to plan for war without their assistance. Sadat issued an ultimatum to the Soviets as well that they had one week to decide to sell Egypt the Foxbat or have them out of the country. By the middle of July 1972, the reconnaissance task force had returned to Russia and the performance of the Foxbat resulted in the VVS and PVO accepting the aircraft for formal operational deployment. 

Sadat launched the October 1973 Yom Kippur War and made startling gains against a complacent Israeli military while the Syrians attempted to retake the Golan Heights in the north. As the course of the war gradually came to favor the Israelis, Sadat was at a point where he was considering accepting a cease-fire. To prompt him to end the war quickly, Brezhnev ordered two MiG-25s back to Egypt to conduct a series of reconnaissance missions over the Suez Canal to prove to Sadat the Ariel Sharon's units had crossed the west bank of the Suez into Egypt and the Egyptian Third Army was completely surrounded by the Israelis. The imagery shown to Sadat forced him into accepting the cease-fire ending the October war. The Foxbats stayed until 1974, but most of their missions by this point had been focused on monitoring US naval activity in the eastern Mediterranean. Once again frustrated that Egypt was still not being offered the Foxbat and that he had no authority over their use, he ordered the Soviets back out of the country again in 1975, ending the last active Soviet involvement in the Middle East. 
Source: OKB Mikoyan: A History of the Design Bureau and its Aircraft by Yefim Gordon and Dmitriy Komissarov. Midland Publishing, 2009, p324-345.

10 November 2010

The Experimental STOL Demonstrator That Fooled NATO

Impressed with the performance of the McDonnell F-4 Phantom II that had just been introduced into service with the US Navy, the Soviet Air Force asked the Mikoyan design bureau (OKB Mikoyan) for a successor to the MiG-21 "Fishbed" that could counter the F-4 on equal terms. The first attempt by the OKB was the experimental Ye-8 demonstrator that was based on the MiG-21. However, the Ye-8 suffered from numerous technical problems that led to the loss of the first prototype and before the second Ye-8 could be flown, priorities with the Soviet Air Force command staff had changed on the characteristics of the replacement design and now emphasized STOL performance as it was felt that the long runways needed by most Soviet fighters were vulnerable to attack by NATO's intermediate-range ballistic missiles. STOL performance would allow the fighter to be deployed to remote areas away from the main air bases in the Soviet Union and Eastern Europe. Mikoyan's studies of STOL configurations were subsequently narrowed down to two configurations- one using variable-geometry "swing wings" and one using lift engines. Although using lift engines would be simpler in theory, swing wings allowed for more space in the fuselage for fuel and weapons. Although Artyom Mikoyan himself favored swing wings, a 1961 report by the prestigious Russian aerodynamic institute, TsAGI, concluded that there were considerable aerodynamic issues as well as construction issues with variable geometry wings. 

While there had not yet been any flight testing of swing wing designs in the 1960s in the Soviet Union, Mikoyan already had experience with STOL jet lift fighter technology, having flown in 1966 the Ye-7 (also referred to as izdeliye 23-01, izdeliye meaning "article", usually in reference to demonstrator or prototype) which was a MiG-21 modified with two lift jets in the center fuselage. Mikoyan divided his team into two groups- one group did further studies of the swing-wing design and the other group studied the same design, but with delta wings and lift jets instead of the swing wing. Mikoyan's nephew, Vano Mikoyan, was placed in charge of both teams. As jet lift had already been flight tested, it was agreed to fly that version first while the other team refined its work on the swing-wing version. The jet lift version was designated in-house as izdeliye 23-01 (a reuse of the Ye-7's designation) and had a single Khachaturov R-27F afterburning turbojet as the main cruise engine with 11,400 lbs of thrust and two Kolesov RD36 lift engines mounted in the mid-fuselage and angled 5 degrees forward from vertical to provide a slight forward thrust vector. A dorsal aft-hinged door opened up during flight along with auxillary inlet doors to provide air for the lift engines which exhausted through a belly-mounted grid of vectorable deflector vanes that could also direct lift engine thrust forward for braking on landing. 
Because the new Sapfir radar system was larger than any radar system used previously, a nose inlet was impossible and the 23-01 had half circle lateral intakes with a central shock cone similar to that fitted to the Lockheed F-104 Starfighter and the Dassault Mirage series of fighters. To augment the lift from the delta wing of the 23-01, the flaps were blown with engine bleed air when lowered. The delta wing resembled that of the MiG-21, but was scaled up for the increased size and weight of the 23-01 design. While there was no radar system aboard the 23-01 nor were there any fire control avionics, a 23mm cannon was fitted under the fuselage just aft of the cockpit and dummy K-23 missiles were fitted under the wings (the K-23 had the NATO designation AA-7 Apex and in operational Russian service was designated R-23). The 23-01 prototype was even painted in the light gray color used by the air defense units of the Soviet Air Force and it made its first flight on 3 April 1967. 

The 23-01's flight test program revealed that it flew just as poorly as the MiG-21 STOL demonstrator that proceded it, the Ye-7. Test pilots noted a considerable amount of instability bordering on loss of control on takeoff due to interactions between the lift jets and the wings. On landing, it was found that the exhaust of the lift jets was getting ingested into the main engine, robbing it of power. The only solution was to increase the landing speed, but then this negated any STOL benefit of having lift engines! Pilots expressed concern at what to do in case of the loss of one of the lift engines on takeoff or landing before the wing had generated sufficient lift. At altitude the lift engines were deadweight and it compromised the maneuverability of the 23-01. The short flight test program confirmed Artyom Mikoyan's favoring of the swing wing configuration, but the aircraft continued flying until the 23-01 could be demonstrated to the public at the Moscow Domodedovo air show in July 1967. With its operational color scheme and weapons loadout, the Soviet Air Force announced its designation as the MiG-23PD, giving Western analysts the impression it was a possible production type. In fact, NATO even went as far to assign the 23-01 the code name "Faithless" as a result, believing that jet lift would be a feature of the MiG-23! After the air show, the 23-01 was retired and donated to the Moscow Aviation Institute for maintenance training and subsequently got scrapped. 

The first flight of the world's first production variable-geometry aircraft, the General Dynamics F-111, in December 1964 showed TsAGI's original 1961 report in error and work on the swing wing version of the 23-01, designated in-house by Mikoyan as the 23-11, was increased. In fact, the Mikoyan designers scrutinized every photograph and inflight footage of the F-111 to determine how the Americans had solved problems that TsAGI only 3 years earlier deemed too difficult to overcome with present technology. The 23-11 made its first flight on 10 June 1967 only one month before the STOL 23-01 was unveiled to the public at Domodedovo. The 23-11 became the first production version of the MiG-23, the MiG-23S (S referring to the Sapfir radar) which used most of the fuselage of the 23-01 and the empennage but added lateral box inlets and a new swing wing. NATO would assign the MiG-23 the code name "Flogger".
The flight test program of the MiG-23/23-11 showed that swing wings very closely approached the field performance of the jet lift STOL 23-01. While the 23-01 at a takeoff run of 1,500 feet, the MiG-23 had a takeoff run of 1,800 feet. Landing the 23-01 required 1,100 feet and the MiG-23 could do it in 1,400 feet. In addition, the MiG-23 proved to be a far more versatile design on account of the performance accorded by its variable geometry wings. Nevertheless, the jet lift 23-01 remains an unusual historical aviation curiosity that fooled NATO into thinking it was the production configuration of the MiG-23!

Source: OKB Mikoyan: A History of the Design Bureau and its Aircraft by Yefim Gordon and Dmitriy Komissarov. Midland Publishing, 2009, p255-257. 

04 November 2010

Credible Sport, the Super STOL Hercules

Following the disastrous failure at the Iranian Desert One rendezvous point of the Operation Eagle Claw hostage rescue mission on 24-25 April 1980, a second plan was drawn up immediately after the failed Delta Force mission to use a specially-modified Lockheed C-130 Hercules to land in the Amjadien Stadium across the street from the US Embassy at which point Special Forces teams would retrieve the hostages and then fly out of the soccer field in the center of the stadium. Under the project name Credible Sport, the crash program would produce a highly modified C-130 Hercules that could land and takeoff from a soccer field with 30-foot high obstacles at each end. Authorized by the Secretary of Defense, the top secret Lockheed project modified three C-130Hs- two would be modified to what was called the XFC-130H configuration within 90 days with the third aircraft to be used for testing the retrorocket packages that were to be installed on the Hercules to give it "super STOL" capability.

The aircraft were modified with fully-powered flight controls along with a 35% increase in the control surface areas. The flaps were modified to be double-slotted to increase their lift and the leading edge roots of the horizontal stabilizer were increased along with a corresponding increase in the leading edge dorsal root fin to provide more stability at low speeds. An extended nose section housed the additional avionics for the mission, the nose section coming from a DC-130 drone controller aircraft. The radar from a Vought A-7 Corsair II attack jet was housed in the extreme nose and an under-nose FLIR package would allow night operations. To provide flight path guidance on the approach into the stadium, a laser altimeter and laser range finder were also fitted. As the mission would be flown directly from the United States, the aircraft were modified with the inflight refueling receptacle from a Lockheed C-141 Starlifter. Five inflight refuelings would be needed to reach Tehran. The inflight refueling system reached back to the wings and was plumbed into the wing tanks. Under the fuselage just forward of the aft cargo ramp was an arresting hook- the plan called for the Credible Sport aircraft to recover on an aircraft carrier in case any hostages or personnel needed medical attention. 

The most extreme modification for the Credible Sport program were the battery of rockets that would give the aircraft its extreme STOL capability. For the landing, eight retrorockets were housed in pairs in sponson fairings on the forward fuselage. Another four rockets on each side of the fuselage were mounted by the main landing gear fairings and were pointed downward. It's believed that the downward rockets were from US Navy ASROC missiles and the retrorockets were from AGM-45 Shrike anti-radar missiles. On approach, speed would be maintained at 85 knots but at 85% engine power to remain at least 5 knots above the stall speed. At height of 50 feet, the downward firing rockets were activated by the navigator for 3 seconds to arrest the descent rate and at touch down, the eight retrorockets deployed out of their fairings and fired with a thrust of 80,000 lbs, bringing the Hercules to a rapid halt. 

For takeoff, four main RATO units that came from the Navy's Standard RIM-66 surface-to-air missile were mounted on each side of the aft fuselage. In addition, six smaller rocket units were installed in three pairs- one pair under each wing mounted on the fuel tank pylon and one pair under the tail unit. The tail unit rockets prevented over-rotation and the wing-mounted units were to provide yaw stabilization should the main RATO units not shut down simultaneously. The ten rocket motors for takeoff provided 180,000 lbs of thrust! This was approximately twenty times the power provided by the C-130's four T56 turboprops.

An amazing series of flight tests proved the concept with the first flight taking place on 18 September 1980, but one problem encountered was hot gas ingestion by the T56 turboprops from the retrorocket packages. Despite this, the modified Hercules could takeoff after a ground roll of only 100 feet and was already 300 feet high just 200 feet after lift off. It was an impressive feat considering that the C-130 itself is about 100 feet long. On 29 October 1980, one of the C-130Hs modified, 74-1683, was conducting a landing test when the downward firing rockets failed to ignite and two of the retrorockets fired prematurely followed by the rest of the retrorockets. This slowed the Hercules prematurely and a high descent rate resulted that caused a hard landing that broke off the right wing by tne number three engine. Quick action by the Eglin AFB fire crews prevented loss of life, but the aircraft was a complete loss. 

With $30 million spent and only two of the three C-130Hs modified, Credible Sport was canceled when the Iranian revolutionary government indicated a desire for a resolution to the crisis with the change in US administration with the November 4th elections that put Ronald Reagan into office. Of the two modified aircraft, 74-1683 and 74-1686, they received the designation YMC-130H. As 74-1683 was a total loss in the 29 October crash, 74-1686 was partially demodified and donated to the Museum of Aviation at Warner-Robbins, Georgia. The third aircraft, 74-2065, was returned to active service. 

This test footage shows how impressive Credible Sport was in action and it also shows in slow motion the crash on 29 October 1980:

Source: Military Aircraft Monthly, Volume 9 Issue 9. "Credible Sport" by Keith Peckover, p46-48.